Grinding wheel



July 15 A1924. 1,501,730 P. SIEGELh GRINDING WHEEL Filed sept. 9. 1921.

IN VENTOR.

'y Z4 f mayb-Jgd ATTORNEYS.

Patented July 15, 1924.

UNITED STATES PHILIP SIEGEL, 0F GUTTENBERG, NEW JERSEY.

GRINDING WHEEL.

Application led September 9, 1921.

To all whom t may concern.'

Be it known that I, PHILIP Smear., a citizen of the United States, and resident of Guttenberg, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Grinding IVheels, of which the following is a specification.

My invention relates to grinding wheels, and is intended particularly for household purposes; the object of the invention is to provide an eicient and simple device of this character, which will permit knives, tools, etc. to be sharpened readily and quickly, which will enable the grinding member to be exchanged without dismembering other parts of the device, and which will possess various other advantages, as will appear from the description following hereinafter.

Reference is to be had to the accompanying drawings illustrating two satisfactory and preferred embodiments of my invention, Fig. 1 showing one form of my invention complete in elevation, with parts in section; Fig. 2 is a detail vertical section of the grinding wheel and its support, on an enlarged scale; Fig. 3 is a horizontal section on line 3 3 of Fig. 2; and Fig. 4 is a detail vertical section of another form of my invention.

At 10 I have shown a casing adapted to be fastened to a table or other support 11 by means of a clamp 12 of usual character, and having journaled therein a vertical shaft 13, which may be rotated by any suitable mechanism, such as, for instance, a crank 14 on a horizontal shaft 15, and bevel gearing 16 connecting the shafts 15 and 13. The parts 10 to 16 may be of any approved construction.

On the upper end of the shaft 13 is mounted rigidly a rotary support or table which in the form illustrated by Figs. 1, 2, and 3 consists of a plate or disk 17 secured to the shaft by means of a square nut 18 screwing on the threaded end of the shaft and pressing said plate against a collar 19 secured to the shaft rigidly.

It will be noted that the nut 18 forms a projection of non-circular cross section extending above the upper surface of the support or table 17 and held to rotate with such table. The nut is utilized not only as a means for securing said table to the shaft 13, but also as a means for compelling to rotate with said table, the grinding wheel or grindstone 20 which rests on said table, in a horizontal position. For this purpose, the grinding wheel Serial No. 499,500.

or grindstone 20 is made with a central recess 21 extending upwardly from its lower surface, but preferably terminating short of its upper surface, said recess being of a non-circular cross section corresponding to that of the nut or projection 18, that is to say, of square cross section,in the particular example illustrated by Figs. 1,2, and 3.' It will be noted that the upper surface of the grindstone, which surface is preferably plane and horizontal, as shown, is continuous and unobstruct-ed, that is to say, it has neither depressions (openings) nor projections-which might interfere with the easy'movement of the blade of a tool or the like across the entire upper face of the grindstone. Furthermore, it will be observed that the rotary support 17 is of considerable extent, preferably engaging the grindstone 20 on the entire lower surface of said stone, so that the latter is supported firmly, and the friction between the large lower surfacev of the grindstone and the support 17 will be sufcient to assist considerably in effecting a driving connection between said support and said grindstone. In fact, I consider it desirable to have the marginal portion of the support 17 project outwardly beyond the outer edge of the grindstone 20, and this projecting portion may be of assistance as a guide or guard, particularly when the curved peripheral surface of the grindstone is used for sharpening purposes, as it may be; generally, however, I employ the upper end surface of the grindstone as the active surface against which the article to be sharpened is held. The article can be moved readily to that portion of the upper surface of the grindstone which is best suited to the shape or size of the article being ground, and by reversing the position of such article, if required, a perfectly even grinding action can be obtained. The pressure of the article bearing down on the grindstone increases the frictional contact of the lower surface of such stone with the upper surface of the support 17, and thus further improves the driving connection. If desired, the upper surface of said support may be roughened or otherwise prepared to increase its frictional contact with the grindstone 20. It will further be observed that the recess 21 is of such depth that neither the upper surface of the nut or projection 18 nor the upper end of the shaft 13 will come in contact with the grindstone, at the upper end of said recess; the downward pressure exerted on the grindstone due both to its weight and to thee-.tool or other articleapplicd its upper face, will therefore-come to "bear eX'- clusively on the upper surface of the support or table l?, through the lower egrindstone surface engaging said table, and the contact between said surfaces will therefore be much better than if the upper wall of the recess 21 rested, even partly, on the upper end of the shaft lf3 or on the upper surface of the nut or projection 18.

Instead of having a projection on the rotary support extendingy into a recess of the `,'giinclstone, l may employ the reverse arrangement, yas exemplified in Fig. THere the rotary supporter table 22 is secured, as by means of screws 23, to a collar 2st held to rotate with the shaft 13, and this support is provided with a central recess 25 into which extends the projection 26 on the lower surface of the grindstone 27. Here, too, the depth of the recess is greater than that. of the projection, so that the free end surface of the latter will be out of contact with the (horizontal) bottom wall of the recess, the weight of lthe grindstone 27 being therefore borne exclusively" by the 'large upper surface of the supporting table 22, where the same engages the lower surface of the grindstone body. Of course, it will be understood that in this case also the cross section of the recess 25 and of the projection 26 should preferably be non-circular, forinstanr-e of the samev shape as shown in Fig. 3.

f lneach of the constructions illustrated. .the grindstone or grinding wheel rests loosely on the rotary support or table, and may be removed therefrom by lsimply lifting it off, without unscrewingr any nuts or loosen.- ingany fastening devices, or dismemberinpT any other part of the device. This is a great advantaeje inthe practical 'use of the device,

as it enables me to substitute quickly grindstones of different material or tineness, c. may be required by the workn Various modifications may be made without departing` from the nature of my invention as set' forth in the appended claim.

lt will be observed, func-her` that the projection 26, in the form of my in\f'ention last described, or the recess 2l. in the form first described, constitutes means` ou the lower surface of the e'rindstone` for centering` it relatively to the supporting table or li' respectively and to the shaft 1S.

l claim as my invention:

i portable grinding;` device comprising a supporting plate mounted to rotate upon a vertical axis and havingan upper plane surface, a cylindrical grinding wheel of smaller diameter than said plate, having upper and lower plane surfaces, and detachably mounted on said plate so as to expose the entire cylindrical periphery and the upper plane surface of vsaid wheel, whereby said wheel may be used either for peripheral or face grinding, one of said elements being provided with a central recess and the other having a projection adapted to be received within said recess, said recess and projection being of non-circular form to compel said wheel to rotate with said plate, said plate by virtue of its larger diameter extending beyond said wheel to provide a guiding surface for articles to be ground upon the periphery of said wheel.` al shaft upon the end of which said plate is secured, and means to drive said shaft,l said shaft projecting beyond said driving` means' a sufficient distance to permit free unobstructed access to said grinding wheel.

In testimony whereof l have signed this specification. Y

PHILIP SIEGEL. 

